TALLAHASSEE, Fla. — State wildlife officials said 429 manatees died in Florida last year, nearly 100 more deaths than in 2008.

The Florida Fish and Wildlife Conservation Commission said Wednesday the increased deaths can be attributed, in part, to cold stress during the winter months of 2008 and 2009.

According to a news release, biologists documented a record high of 56 cold stress-related deaths in 2009, more than double the five-year average. They also found high numbers of boat-related and newborn deaths.